I D/L Q4G 1-5 setup.exe. It took almost an hour to get the 1.0 Gb file. Now it is stuck, showing it as an unconfirmed download.

Any ideas?

How are you downloading it? Browser or downloader? If browser, try downloader and vice versa. Or try different browser.

If you experience unfinished downloads, install and use the GOG Downloader. It's able to resume the download and installation at any time and also checks for corrupted files. If it finds a broken file you don't have to download everything again, but just a small part, as the downloader gets one download in several smaller pieces and puts them together before installation.

As for your current download, try to pause and resume it in your browser, while you're logged in at GOG.com.
Many browsers support this. If not, go to your download directory and rename the file to setup_quest_for_glory_pack_2.0.0.32.exe if it's different and simply try starting it. Maybe the download was finished and the browser just didn't noticed it correctly.
(but make sure your system shows all file extensions before you rename it; Here's a how-to show file extensions just in case)